Shader "Tang/imgCut"
{
    Properties
    {
        [PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
    _Color("Tint", Color) = (1,1,1,1)

        _StencilComp("Stencil Comparison", Float) = 8
        _Stencil("Stencil ID", Float) = 0
        _StencilOp("Stencil Operation", Float) = 0
        _StencilWriteMask("Stencil Write Mask", Float) = 255
        _StencilReadMask("Stencil Read Mask", Float) = 255
        _ColorMask("Color Mask", Float) = 15

        //my member
        _Radius("圆半径",Range(0,0.5)) = 0.3

        [Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alpha Clip", Float) = 0
    }

        SubShader
    {
        Tags
    {
        "Queue" = "Transparent"
        "IgnoreProjector" = "True"
        "RenderType" = "Transparent"
        "PreviewType" = "Plane"
        "CanUseSpriteAtlas" = "True"
    }

        Stencil
    {
        Ref[_Stencil]
        Comp[_StencilComp]
        Pass[_StencilOp]
        ReadMask[_StencilReadMask]
        WriteMask[_StencilWriteMask]
    }

        Cull Off
        Lighting Off
        ZWrite Off
        ZTest[unity_GUIZTestMode]
        Blend SrcAlpha OneMinusSrcAlpha
        ColorMask[_ColorMask]

        Pass
    {
        Name "Default"
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #pragma target 2.0

        #include "UnityCG.cginc"
        #include "UnityUI.cginc"

        #pragma multi_compile __ UNITY_UI_ALPHACLIP
        #define PI 3.1415926

        struct appdata_t
    {
        float4 vertex : POSITION;
        float4 color : COLOR;
        float2 texcoord : TEXCOORD0;
        UNITY_VERTEX_INPUT_INSTANCE_ID
    };

    struct v2f
    {
        float4 vertex : SV_POSITION;
        fixed4 color : COLOR;
        float2 texcoord : TEXCOORD0;
        float4 worldPosition : TEXCOORD1;
        UNITY_VERTEX_OUTPUT_STEREO
    };

    fixed4 _Color;
    fixed4 _TextureSampleAdd;
    float4 _ClipRect;
    float _Radius;

    v2f vert(appdata_t IN)
    {
        v2f OUT;
        UNITY_SETUP_INSTANCE_ID(IN);
        UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT);
        OUT.worldPosition = IN.vertex;
        OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);

        OUT.texcoord = IN.texcoord;

        OUT.color = IN.color * _Color;
        return OUT;
    }

    sampler2D _MainTex;

    fixed4 frag(v2f IN) : SV_Target
    {
float2 uv = IN.texcoord.xy;
        float4 col = IN.color;

        float2 nor =float2(0.5,0.5)-uv;
        if (length(nor)>_Radius)
            col.a = 0;
        
clip(col.w-0.01);
        half4 color = (tex2D(_MainTex,uv) + _TextureSampleAdd) * col;
        color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect);

#ifdef UNITY_UI_ALPHACLIP
         clip(color.a - 0.001);
#endif

         return color;
     }
         ENDCG
     }
    }
}